


300 Days of Zim

by depriviolent



Category: Invader Zim
Genre: Alien Biology, Gender-neutral Reader, Other, Pegging, Porn with way too much plot, Reader Insert, Slow Burn, and it being mistaken for weird human biology, kindve...?, last tag was the whole point i wrote this and it....got out of hand from there
Language: English
Status: Completed
Published: 2019-10-11
Updated: 2019-10-11
Packaged: 2020-12-07 23:11:22
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 9,255
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20983961
Author URL: https://archiveofourown.org/users/depriviolent/pseuds/depriviolent
Summary: Everyone seems to know what his problem is - but you. And maybe that's why he's taking such a liking to you, the first person he can have a clean reputation with. Or maybe he just wants to steal your liver.





	300 Days of Zim

**Author's Note:**

> havent written a reader insert in... years.  
havent used this account in... years.  
but cringe culture is dead and zim is back so lets help a short angry alien get off!
> 
> also, reader is completely gender neutral but dfab. also i am a bit delirious with illness so i beg forgiveness if i missed my own beta of this. thank u.

You aren't from around here. In a way. You've been here in town, but you've been many places across the country, across the world because when your parents need to be somewhere, so do you. And when you have been everywhere, it's easier to not get attached and stay within the family, learning from them. 

So you've been here in town. 

You haven't moved out of it, staying behind as an adult who can make that decision, just like you can decide to go to college and get an education among your peers you've never met in your life. You seem to fit in well, even out of your comfort zone. Everyone else has their quirks, after all. Who's to judge the awkward unsocialized? 

From the laughs, the rumors, the buzz, you can tell no one else really comes and goes. Between the 3 classes in your week, there's a similar assortment of people. The different faces are brought familiar by their friendliness. Even towards you. 

One classmate in particular helps you get adjusted. A leather jacket in the summer man who, not that you're judging, can't pull off such a cool look with his boyishly freckled cheeks and unmaintained peachfuzz. And his tooth gap you can see his tongue clicking behind whenever he gets annoyed.

Dib gets annoyed very easily. Never with you - yet. The two of you seemed to have clicked instantly over your starry-textured phone case and just kept bonding over space since. You can't imagine Dib getting annoyed with you. But there's one classmate reserved for it.

He seems to be… at odds with most of the other students. Before the second quarter, the same name always came from friends chatting. Someone with a reputation, you figured. Troubled back in skool, detentions, fighting, blowing up the library? You don't find some of this small town humor funny. It makes you less keen on believing the buzz built by people who "grew up around him, trust me, he's… weird." Even from Dib! Who had complained about being bullied just the same! 

Well you're not one to judge. You want to meet him firsthand, to decide for yourself who he deserves to be. This… this… 

"Zim, I'm going to knock you off the table if you don't get off my bag."

"Oh? Is that a threat?" 

You can hear them from the open door to Creative Writing II, trying to check you didn't leave your pencil at home _ again _ among a knapsack in desperate need of organizing. 

There's Dib. Flat, unamused, just woken up. 

"It's going to be."

You've been talking to him for half a year at this point, it's no wonder you can recognize him. But you aren't remotely familiar with the other voice. It's unlike any teacher, any student. If you'd heard it before, you would know.

It's just so loud.

"Make due on threats, wormboy. Do you _ want _ to be even less feared than already?" 

Not as loud as the very obvious thud of a body hitting concrete. Oof. 

You inch towards the door after it, nervous like it's the first day all over again. After all, there's never any new people in town. You aren't quite ready to have another face to remember.

First is Dib when you peer in. He rests on a hand, yawning. He doesn't notice you approaching, too busy staring at the floor. Someone on the floor, you realize, biting down the anxiety to step all in. 

"I expected that! Zim wears off on anyone over time, even the inferior." 

Dib just rolls his eyes. There's an air of being used to this. This is when he notices you sliding into your usual seat by him. His shoulders twitch. "Way to scare a guy."

You chuckle awkwardly. 

Usually you'd have a cheesy retort but someone else takes your spot. A gloved hand on the table pulls them up and it's finally when you're face to face. It's… a teal face. You wonder if it's makeup with how heavy the rest of his look fits it - or if it's actually his skin. His green cheek is scuffed up from hitting the floor, mouth pulled into a pout. Bagged eyes squinting at you. Dib's fallen bag hangs off a shoulder. A hoodie you swear you've seen Dib wear before on a body way too small for it.

This person is definitely small.

You have to look away from the eyes digging into you. Then comes a laugh. 

"New kid! Many stories I have heard of you! Is this not them, pig brain?" You feel like you're being conducted on stage by an overzealous director, the stares of classmates in further rows obvious. But only briefly. The usual chatter begins again. Like this is normal.

Something clicks in your brain at that. 

Dib's starting to answer his friend when you butt in. "Oh, well, I'm not so new anymore. But you're new! To me! Are you Zim?" You hold a hand out.

He just stares at it. Dib sighs. "You shake it. How long have you been here?" 

There's a scoff. "I know that, _ Dib. _I was making sure it was safe first." Your hand is grabbed rather forcefully, leaving you unprepared for cold leather on your palm and a tight grip that pops a knuckle. "Yes I am Zim! My reputation precedes me, as usual." He's louder up close. "Condolences for leaving you waiting. Securing a seat in…" This person, Zim, looks around the room. His eyes settle on the whiteboard. " 'Creative Writing' was a feat almost too daunting for even me… but! I must… begrudgingly thank Dib for making it less so." His voice hits a normal octave and you smile. It's far more pleasing like this. Almost soothing to listen to.

Dib smiles too. He's clearly amused. "You're welcome, bugboy." 

"Well… Well, Zim! It's awesome to finally meet you," you manage. 

"Naturally." Soothing and funny now. He squeezes into the seat on the other side of you. "I look forward to learning with you. Creatively." 

"Yeah! You can use my notes if you need to catch--" 

"NO!" You clench up in your seat, shrinking. Zim's mouth opens to continue. He hesitates though, clearly glancing over your shoulder. In the silence, you start to relax. Especially once you notice what looks to be… purple? A purple shade crosses where a nose bridge should be, isn't. How'd you not notice his lack of any sort of nose? "...No. That will not be necessary. I require no catching up. If, however, you need assistance in this or other classes… you've met Zim." He offers a way too big smile.

You can feel Dib pinching his very much there nose bridge behind you.

You grin nervously back.

* * *

Zim… has a lot of energy. Which is an understatement. He's bouncing off the walls in class, unable to sit properly still, unable to not ask and ask and ask questions until lessons end on tangents light years from what the board says. Chewing on hoodie strings and you can hear Dib grumble under his breath about how "Zim, that isn't yours to chew!" and hissed "You chewed them first!" 

Dib and Zim's bickering is endearing. You can tell they've known each other for a while, definitely better than anyone else in this tiny community college. Better than the rumors you knew weren't true. Blown up stories to jump off a clearly eccentric man who had to be a far more rambunctious kid. You've been there. You get it. 

It helps you click with him. This shared isolation for being an angry, high-energy person in a world that didn't quite want that. Not in as many words, of course. Zim isn't very forthcoming with his feelings. Unless they are about himself. He loves talking about himself. How great he is. How hard he worked to get here. How lucky you are to hang out with him - which you start to.

Dib and Zim seem to do a lot of hanging out but you can pick up how annoyed Zim gets about Dib's job at the only coffeehouse in town, which annoys Dib (that clicking!) back. Seeing Zim wanting to yell about it but just shrinking into his chair in the college lobby grumpy reminds you of a kid. A kid failing to stay in another new home they just got used to, failing to keep friends who already got used to each other. A kid who's learned to repress the kicking and screaming. 

So you start hanging out too.

You can tell he enjoys walking around town with you, going off on the local tidbits he's picked up in the ten years he's been here. How many times they've gotten on national news for things you do, now that you think about it, recall seeing while travelling. Or the alleys he got lost down trying to navigate, ones he proudly takes you through with ease. Or walking his equally peculiar dog to buy it food you thought would kill an animal but maybe the breed's just that sturdy. Or the coffee shop where Dib works, where he looks less than happy but gives you both free drinks without hesitation, whispering to you how he's glad you're doing this "but don't dare tell Zim. He doesn't need the ego boost." 

_ You _ enjoy this. It's more socializing you've had in two decades between the two men. Especially Zim. A certain warmth envelopes you when he's around. He practically dances into your classes, eager to babble to you and sometimes even listen. He's started listening more, inquiring about you for a change. Texting you on days off, finding out where you work - a far less fun department store - to meet you if he can't pester Dib. He has nothing but free time he constantly needs filled and you've become his go-to for it. 

It makes you wonder if the same fluttering bothers him when you're around as when you see him. 

You ask him. 

It's a chilly October night and you work up the courage to ask him. Not enough to not do it through text though. **hey are you awake**

The rapid fire **DUH. I DO NOT SLEEP. **makes the fluttering worse. You really aren't going to get to just send this and wait for his morning reply. But this is cowardly enough to not do to his face. 

**i need to talk ** You stare at your phone, bite your lip, and add more before Zim can answer and you can give up. **this is probably sudden because weve only been hanging out for a few months now but i think i like you. like seriously like you. like id be into dating you. sorry.**

The same chills you got shaking Zim's gloved hand trace your spine. Relief at just getting the words out wants to set in but the sudden disappearance of Zim typing makes it melt into the butterflies. 

It doesn't help it doesn't return for an hour.

An hour of feeling on the verge of hurling, pacing your apartment, drinking too many cups of water that collects hard in the pit of your gut. The time seems to drag. You force yourself to not keep checking your phone. You go to try to watch late night cartoons. Impossible. You try making a snack. Revolting. 

You're miserable. And now your perfect atmosphere at class is ruined.

_ BZZTP! _

Or not.

Heart trembles as you pick up your phone. Chokes you as you read **WE SHOULD GO ON A DATE. ** and a followup **RIGHT NOW.** Oh God.

The cold is piercing in the park, darkness suffocating. You stand alone by the benches feeling like a fool for agreeing to this. Because you should've waited until tomorrow or because now you will be stood up and laughed at for catching feelings for the tiny weird guy from Creative Writing II -- 

"YOU!" 

You nearly trip over your feet snapping to face Zim. He's in the same position, clanky platform boots not doing him any favors. He comes to an awkward sudden stop. Breathing looks wild in the fog. He looks so much cuter in his baggy winter clothes. 

"WE… NEED TO TALK. WALK." 

So soooo cute using his loud voice. Booming, end tampering into a softer, almost uncertain place. Your heart could weep. 

You just nod, follow. 

Save for the distant cars on the freeway, it's quiet. Eerie when around Zim for so long. The green man continues to be silent besides you. The only sounds are the last of autumn's leaves crunching under your feet, a crunch of each little wing beating in your stomach deciding to settle or take flight. 

He clears his throat dramatically. "After careful consideration, you could… perhaps… be a decent partner for Zim. Being around you is interesting and you have the incredible capacity to not completely annoy me." 

You swallow the knot in your throat, staring forward into the dimly lit path. You've been around Zim just long enough his less than romantic speech still makes your face warm. "I like hanging out too."

"Yes, yes, hanging out." You watch him shuffle from the corner of your eye, rubbing his hands together. There's that pinch of purple in his cheeks "We should keep hanging out - we _ will _keep hanging out." 

"I'd… l-love that." Throat feels looser. Body less tense in the walk. Even the following silence hits less horrific, more gentle. 

He really does feel the same way. Right? That's what he was getting at? Zim actually likes you and isn't going to mock you for catching feelings so easily or blow up your apartment like Dib had joked when you asked him for advice. Not that Zim had the ability to do such a thing… absolutely not. But he had the ability to reject you because his life seemed to not need a partner squeezed in - you can relate from a childhood of keeping an unhealthy distance from others. 

Not anymore though. 

Your back straightens, doofy smile popping up as Zim gets closer. Wraps his hand around yours in a brief death grip. Brief before he tries to hold more carefully. His thick nails still poke uncomfortably but it's charming. "You seem better than my last date. So I can try this again." 

"Y-you too." Speaking is difficult. But he's worth the effort. "W-Well my last date was just some tindr pick up - not that I'd only do quickies with strangers! I do want to find someone! I do want to be serious. Can I kiss you?" Your face goes dark red. 

Zim stops walking. His grip gets tighter. "Can you kiss me?" 

Oh you hadn't meant to ask that. Maybe on the third or fourth date but not _ immediately _! His face just looks so cute, the moonlight shining off him like a spotlight, and his lavender eyes looking up at you in adorable confusion. You smile too big, can't speak. 

He's thinking. You can tell. Eyebrow crease pinching. "You have Zim's permission." Heart stutters at how much quieter his voice is. "Don't make me regret this." 

"I…" Swallowing doesn't take away how wet your mouth feels, too full and gross to be touching someone else's. Too soon to be. "I won't?" 

Your free hand itches. You want to hold his chin when you do it, tilt him up into it, but you worry he'll feel even smaller by you. You have to opt for leaning down. Leaving a quick chaste peck on his lips that is still enough to darken both your faces. You expected your embarrassment. Zim's is surprising. 

More surprising is him using your hand to yank you back down, resting on the toes of his boots to kiss you back. Far less quickly in a press that makes your gut burn fierce. Once it's done, Zim lets go of your hand. Steps back.

You can tell he's holding his breath up until he wipes his mouth off. Then he breathes too quickly. And then he's leaving. "THIS. WAS FUN. BYE." 

You watch him run off with your heart deafening in your ears. The pounding gives you a headache and his sudden departure doesn't do much but make it worse. Your own breath catches when you see Zim nearly fall flat on his ass stopping abruptly on the icy path. He slides, hesitates, turns around. Clear death grip on a tree.

"WE'RE DATING. WE'RE DEFINITELY DATING NOW. I'M OFFICIATING IT. BYE." 

And he's off again, pushing off and gone.

You can't believe it. It feels like a hazy dream, the best you've ever had. Meeting this peculiar, exciting man once you stopped isolating from the world, being his friend, his _ partner. _Getting to kiss him?! Your face still burns over it through brief sleep, walking into Dib's morning shift for a need to tell someone.

He seems generally shocked. "Well the last time he dated anyone was when I -- when we were like 12. I don't think he got what was going on though. Not that I was sending you to your death but I didn't actually think you could… work out." Dib sprays water in his face when he cleans a milk pitcher. He grumbles. "Figure he's been studying human romance enough to understand it now. Not enough to not need help though." 

You giggle nervously. "Help?" 

Dib wipes his face off. "He practically broke my window to wake me up after you texted him. You should be proud. I've never seen him actually nervous over someone before." 

You are proud. You hold your reddening face. Dib hands you your drink with a smirk.

* * *

The nerves die, eventually. 

Dating Zim feels like hanging out with Zim. He acts like it's the same thing for the most part, after all. Still walks around town with you, still texts you random nonsense he discovers out and about, still waits in the school lobby for you after class. It has the added bonus of him constantly holding your hand now. He figures out how to do it without cutting you on his nails, though his gloves never come off. Whatever he's comfortable with. 

He doesn't get comfortable very easily. He doesn't try to kiss you again until weeks later, nuzzling your face and making a sound you don't want to call a purr but… 

He doesn't move away instinctively from your kisses, even when you ask first, until much later. 

And being held… You shamelessly thought about having the small man in your lap, holding him in tight embraces, enjoying his presence up against your chest. But he doesn't like the feeling. He admits he feels suffocated. You can meet in the middle with him just resting in your arms. 

And you don't need more than that. This is enough. You're just so happy to be with him, to sit in his home watching old movies with his head at least brushing your chest, his dog curled up at your feet. Or sitting in your car with his boots up on your dashboard delighted to get to tell another story of another place you've lived. 

That's where you finally consider going further. Not that you hadn't thought about it way too much by now. There'd been creeps of it before you even dated, naturally. It's just that something about how he slouches in your passenger seat, how your old cringey Hot Topic shirt sits just low enough on his thin shoulders, how he laughs so earnestly at your shitty jokes, something about him now makes you want to verbalize the thoughts. Here in the parking lot of your now former job. (Not as of this afternoon. It's just a nice empty spot to park.)

Risky but Zim always appreciates risky. 

You lean close. "Can I kiss you, Zim?" 

He just kisses you as an answer, grinning huge against your lips. 

Oh you think you might love him. "Not to jump the gun-"

"Oh, I left that at home, do not worry."

"...do you want to try something?" 

If he had eyebrows, you are sure he would have raised one. His head tilts, grin not fading. If this means he got what you wanted to put out there, you honestly can't tell. Zim isn't exactly the best at picking up on subtleties. Unfortunately you have to be blunt about this or risk him having some breakdown in your car. 

"If… If I ask you if you want to fool around, would you understand what that means?" You feel so condescending asking it. 

Zim snorts. "Obviously I understand that!" Uh huh. 

You gulp. "Then…" Stare at him with a gradually reddening face, hoping thats sign enough for him. But he just stares back, leaning against his car seat too casually. The raglan shirt dips enough you can see his jutting collarbone and it gives enough courage to speak up. "Do you… want to fool around? Right here? Now?"

Zim frowns. "Fool around right here?" 

"Right now." 

"Right now."

_ Holy shit. _"Zim, can I touch you, like, intimately?"

The purple sparks on his cheeks. Guess he understands that. He sits up straighter, feet going to the floor. Coughs before breaking out a clearly strained smile. "I mean-- your peop-- Isn't it _ weird _ to do… _ that _ in public?" He doesn't turn your offer down, which makes you feel less of an idiot for asking. 

The other part… he is right. "Yeah but… there's not really anyone around."

"We're around."

"I've already been fired so it's not like I'd get in trouble if someone did come around."

"That's something couples do. Eventually. But public fornicating… I don't know if I could even--"

You laugh too loud. "Oh my God, we don't have to like. Fuck. I just want to make out with you." You feel out of breathe, chest heavy from the nerves, the exasperated talking. "If you'd… want to. Make out." 

"_ That's _ fooling around." Zim mutters under his hand, rubbing his face. He's not looking at you. Staring vacantly forward in thought, Zim seems to blush more. You think he's blushing. Is that how his skin condition works? It's only when he clicks back does he turn his usual laugh back on. "Which I _ knew _! I was preparing for this! Albeit… much further down the line than today. But Zim is genius enough to handle a change of plans!"

The sweat is pooling under your collar. "...I...Is that a yes?" Zim's leaning on the cup holders, grinning. The nerves are definitely far away from him now. You wish you were as good at disguising yourself as him. "O-Oh that's a yes." 

"It's a yes." 

The two of you have kissed before, obviously. Kissed a lot, actually. Casually, quickly, maybe a short pause as a goodbye at the end of a date but nothing more than chaste. Zim is very chaste. You wondered often if he'd even been in these situations before, ever even thought about them like you couldn't help fantasizing. He is just a guy. Just another guy with way too many hormones like every other one you'd met. 

You've kissed. But this feels so different. His lips on yours when he _ pushes _into you, braces himself on your shoulder is completely new. Exciting. Making your frame feel so small besides him for once. Head tilting closer as his fingers are on the nape of your neck. He knows what he's doing - or at least done enough research to fake it. 

You figure the latter, even as his tongue traces your teeth. This is new for him. He's clearly struggling to breath. It all comes out hard and hot on your face when he does break away. He holds it in to shove his tongue into your mouth. 

It makes you cough, tugging at his shirt. Barely getting out, "Get in my lap… please. This position sucks." Tugging. 

Zim climbs over immediately. Awkwardly trying to fit under the low ceiling but you take advantage of him sitting so tall on you. His shirt rides up, exposing brighter green hips. His bones sit too far out on them. His body looks so scarily tight under his baggy clothes. You still kiss it though. You can be a nervous wreck later. 

You half expect Zim to be unhappy with your lips on his naval. And if he were, he'd be back in the passenger's seat grumpy and snapping. But he isn't. He's sighing. Such a new sound. He makes it again when you kiss it again, hands travelling under his shirt, up his sides. 

He is so cold to the touch. Your palms feel like they are grasping ice on his chest. 

He braces the ceiling, giggling. "You're warm." 

You smile at it. Lessen as you rub his chest and find… nothing. It's completely flat, smooth. More so when he arches into your touch - "Really warm." - but you figure some people don't want nipples grafted back on afterwards. There has to be an afterwards. Why else is he usually so tense about intimacy? 

You can't fathom any other reason there'd be nothing left besides the delighted sounds as you travel back down to squeeze his ass. Kiss his stomach again. The icy skin on your face calms the heat scorching your cheeks. Your mind is too boggled over _ him _ to get deeper into anything else. You just know you're nervous but so, so into this man. 

You nuzzle his stomach. "You… you can sit down. Please." He always listens when you ask nicely. He's back at face level. You know because he starts kissing your face with a goofy grin plastered on his. 

"Frankly, I didn't think I could ever be up for this debauchery. But when you _ date _someone, I can see anything can happen." You tug at his belt loops, teeth grazing your ear. His voice is almost heavenly right in it. "Human desire… is fun." He nips. 

You tug, breathing catching. "Can I… here?" Hands grasp his thighs. They just barely twitch. 

Zim laughs, thundering in your head. "Why not? What will you do, I wonder?" He can clearly hear you swallow. "That means yes." 

Oh, you have permission. That's completely terrifying but, as he said, completely and utterly fun too. You can't help matching his grin at his motions. You never could've expected him to be so into this. Tongues on the curve of your jaw never factored into your daydream scenarios. Only hovering above him perhaps, doing most of the work for someone who either didn't get what he needed to do or just didn't want to. 

Zim wants to. You can be sure of that. Your fingers tremble unzipping his jeans, his mouth back on yours. Just for kisses. Just to muffle a surprised sound as you trace just beneath his boxer's bandwidth. Even those are too big on him. He should let you shop for him. Or sew. 

There was no trail of hair entering it, so you shouldn't be so taken aback by how smooth he keeps himself. Stubble doesn't even scratch your fingertips. It's simply skin that starts to get just a bit warmer the lower you dip. Warmer and wet.

Very wet. 

Zim nuzzles into your neck when you find him. What has to be his clit twitches on the pad of your thumb, hard. For some silly reason, you're shocked he has such normal anatomy. But he's only human in the end, no matter how different he looks. A human just as sensitive as anyone else. The sound he makes you can't quite place as a hiss or a gasp but you like it nonetheless. A kiss is placed on his cheek. "Let me know if you wanna stop at all… o-okay?" 

"Obviously I want this since you still have both hands, idiot worm." It was a hiss. He is hissing at you, getting quieter as he mumbles to himself. "Obviously been on this dirt pile too long -- I shouldn't even be able to do this… stupid human hormones…" 

"...I'm just checking." You ignore whatever he's going off about because clearly he would prefer that. Clearly he would prefer you get inside of him already. You personally want to. Have wanted to for a shamefully long time. 

He's wet enough it's easy to slip a finger inside him (Zim that wet for you -- oh your ego), palm grinding into his crotch. Hard. You can be for certain that was a gasp.

"That's… so weird," he grunts. 

"Why? Never done this before?" you laugh nervously. Half-jokingly. Curling your fingers and feeling him tighten around them.

"No." A hint of vulnerability comes out. "No, I've _ never -- _nobody has ever -- I'm not supposed to be able to - not to like this." 

"Do… you like this?" Your other hand rests on his back. You leave sweet, gentle circles. Hand in his jeans digs deeper. 

He clearly clenches his teeth before spitting out, "Yes." An idiot grin hits your bright red face. 

It's not long before Zim ruts down into your hand, holding your wrist to keep it in place. It's uncomfortable but the sounds right in your ear make up for it. You expected him to be loud, to practically signal to everyone in the parking lot that, yes, you were fingering him and, yes, he loves it. It's not what you get, even when your three knuckles deep and your palm is slick beyond anything. 

Even when you kiss his neck, Zim's breathing only hitches.. He's trying to control it but it's ridiculously shaky, the loudest noise he makes as he just gets quieter. You have to strain your ears to hear what you _ know _ is a whimper.

"You _ really _ like that, huh?" Your chuckle comes out strained. "Whoever told you you can't probably just didn't know how to make you cum." 

"Am I going to cum?" He sounds frightened. You rub his back to soothe whatever scares him about the idea. Scares you that anyone could have made him feel this way about his own body. Nobody who could put any doubt in his mind of himself deserves to even exist around him. The thought, the crack in his voice when he gets out a "I ca-can't cum -- I'm not--" makes your chest tightens. His arms both hug you as your palm grinds into his clit. His voice bubbles in his throat.

"But you can. You're allowed to, Zim."

"You-You don't _ get _ it--"

"I don't but I know I'll make you cum. You deserve to cum. B-Because you're just that incredible and…" Your mouth feels so dry suddenly. Your wrist is about to snap. He seriously better be close. Your tongue clicks. "Such a good, handsome, perfect boyfriend. You're a good boy, Zim." 

He seems to laugh. "I'm a good boy?" 

"A _ really _good boy." 

He seems to choke. "I'm not -- _ Oh. _ " His hand yanks at your hair. " _ OH. _I MIGHT -- I AM --!"

You try to rest your face on his so he knows you're smiling as soothingly as possible. Try to get your free hand inside one of his so he can squeeze it. He might break your fingers in half. "We're almost done… y-you've got this, Zim." 

His body shakes against yours, insides tightening around your fingers, and he seems about to actually scream. And he likely would have. And it would've broken your eardrums, and whoever was in the store working would hear it, and it would've been worth it. But he doesn't. 

What you do get is the start of a genuine sob before two rows of sharp teeth are in your shoulder, biting down _ hard _. So hard you immediately start going dizzy from the pain and the blood clearly starting to drip down your collarbone and chest.

"HOLY S-- ZIM!" 

Zim's whole frame convulses. Once. Twice. He bites harder. You clench your own teeth, torn between passing out or being over the fucking moon from how much wetter your hand is getting. At least if you die here, you can say you got Zim to squirt first. That'll show the bastard who tried to ruin this for him. 

When he does unlatch from your shoulder, the fresh air makes every bite mark sting like nothing you've ever felt before. The blood makes the inside of your shirt sticky, the sweat already doing a great job of that. You get both hands out to try to help Zim lean into the steering wheel, realizing one is way too disgusting now to attempt.

The blood loss is getting to your head already because you seriously think the cum all over your fingers is bright blue. "I… might need to go to the hospital."

"I've never come before," Zim mutters back, your blood smeared all over his lips and chin. Even through your blurring vision, you can see he's trembling. Almost even looks like he was crying at some point. "I've never…"

"Not like that, right?" You laugh.

And then everything goes completely black.

* * *

You ache for weeks. No matter how many layers of bandages or how many painkillers you take, though Zim struggling to open childproof caps makes laying in your apartment worth it. 

It's all worth it. The look on the nurse's face when you came to in the emergency room, the laughter that almost made Dib pass out himself when you tried to be vague about the wound healing, the homework you missed in all your classes. You needed the time home anyways. You had some things to buy. 

Zim makes sure you have your syllabus for every class. That you know he _ really _ didn't mean to nor think he was about to do what he did. That human blood tastes revolting. You bluntly, finally, get him to stop apologizing every time you see him by reminding him how heavenly he sounded right before he almost killed you. It shuts him up immediately.

You don't mean it bitterly. Frankly, it's all you can think about, especially when neither of you are quite sure how to approach anything like that again. Zim clearly has a strong reaction to sex. You are mind numbingly, stupidly in love. It's not the best combination. 

Your relationship returns to normal though. Where you were watching cheesy movies, Zim watching you bake food he's always allergic too, you watching him upgrade your phone in ways you thought not physically possible. 

Making out and _ only _ making out, with Zim hovering over you no longer so afraid of hurting you again. It makes you want to do more again and soon. You only remember months later, when you've fully healed up, that you made plans to go back in ways you pray won't get you hospitalized. You let Zim know about them so he can gauge if he has enough self control.

He looks less than confident after you do. He keeps doodling flying saucers on his latte cup, the emptiness of the shop's lobby probably not helping how not intimate this place you picked is. "We can simply never have sex again. Why is that not a possibility?" 

"Like you could go never having sex with me again." 

It's a joke but Zim nods. Makes brief eye contact with you. Clenches his teeth. "No. No I couldn't." He snaps his marker in half. "Why is everything here so weird?"

You try to drink your own latte, scoffing. "Says the guy who mauls people when he finishes?" 

"I TOLD YOU I HAD NEVER DONE THAT BEFORE." He's just loud enough you can see Dib on his drive-thru headset smiling at you, clearly about to start laughing again. Obviously the few coworkers of his keep on but give you both dirty looks. 

Speaking through your flush is the only way to ignore them. "Yeah because you seriously went twenty some years never once experiencing an orgasm."

"I went a _ lot _longer than twenty fucking years..." Zim rubs his face, leaning back in his chair. Even if you're coming dangerously close to fighting, you have to admit he always looks cute. Your wardrobe seems to have replaced whatever he was stealing from Dib. "... Maybe. MAYBE. I am interested in trying this again." 

You raise an eyebrow.

"My only condition is it's not in your disgusting little car again." 

You roll your eyes. Crossing your arms over your chest to think it over. Not that going back to your car was a remote possibility. It was a horrible idea to begin with and you both know how lucky you are nobody caught you. 

Clearly you needed more space. Zim could have arched back instead of into you, could've just not been forced to sit on your lap… being so darling shaking through his coming climax… rocking his hips to make your fingers hit just the right spot over and over… going from so overconfident to unable to even get a full sentence out -- oh you need to do this again. The heat on your face is embarrassing. "Let's do it at my place this time. Nobody could bother us then." 

"... That could work. It's closer to the hospital." He grins in an unexpectedly normal way. 

* * *

Meeting him with the intention of hooking up, instead of it just becoming a consequence of the night, is harder to get ready for. Your tiny apartment is spotless when it's almost time. It usually is. Zim keeps everything around him clean to a fault and when you've been together so long, your place is obviously his to drench in bleach. You aren't the messiest to begin with but you still double check everything up until the front door buzzes.

Zim walks stiff to your bedroom, tugging on his hoodie strings. You'd asked if he would want to save this for later, to enjoy a normal evening that built to it. He didn't though. You appreciate how honest he is when he has you take him straight to the bedroom - "I'm worked up _ now _. Why would I wait for when I'm not?" 

Emotionally, you don't know if you are where he is. Desperately you want to do this. You've been wanting to ever since you started going delirious from blood loss. But faced with no build up - perhaps a movie, cuddling on the couch turned to kissing turned to carrying him to bed- means you have to sit in the worry you aren't ready for this. That you can't do _ this _ as well as jerking him off. 

"That is it?" 

"Um. Yes." 

You'd just be even more scared later. Zim was right. It should be right now. 

Zim sits cross-legged on your bed, examining everything you brought. It's all pink. Obviously. The contrast against his skin was all you could think about months ago. It looks almost neon on his black gloves. "I did look up what exactly this is. I have never _ heard _ of it. It's a niche fetish, yes?" He examines the bottle of lube by his knees. Face goes pale, at first. Mumbles, "W-Water-based." 

You squeeze in next to him as he reads the ingredients list. "I… guess? I don't think it's as niche anymore. Or even really a fetish? It's j...just kinda a way of. Of banging your hot boyfriend when you don't really have a means to." You choke on your laugh. Zim is too fixated on the bottle. "...I have a different brand if you'd rather I grab it."

No response until he smiles in relief. "That will not be necessary. This won't melt my insides." 

"Melt your - Is there a certain chemical you're allergic to?" You examine the bottle, feeling stupid for not even considering that. There's already so much he can't do. Why didn't you think of that?

"Yes, yes but this is free of it. We can use this. I presume the material of… _ that _ won't harm me either." He gestures at the final, most important element of the night in his other hand. 

"I-I hope not. That'd be awkward." 

"Very."

"But wouldn't you deserve it a little? Like… for almost killing me?"

Zim stares at you blankly. The joke doesn't remotely land. You clear your throat. 

"Okay so. You don't like people above you so missionary is out of the question. Is there, like, a specific position you want to do?"

"I refuse to be on my back."

"That's what missionary is, Zim."

"Ah." He scratches his chin in thought. Clearly that's a no. 

"Okay how about…" You take the items from his lap, setting them down on the bedside table. "We see where we end up. Yeah?" Zim looks over his shoulder at them. Then back to you.

He nods. And grabs your face to kiss you. 

He's changed from when you first started dating. Never nervous but often very clumsy, clearly hoping whatever videos he saw he was copying right. By now, nearly… God, over a year later, he works off his own experience. What he knows you like. You like his fingers ghosting the back of your neck or his tongue against yours or your chests flat together, breathing together. 

Zim uses that to push you to _ your _ back. Worm his knee between your legs to rest against your pelvis, the man grinning above you. It often ends there, his leg, but you can never place if it's purposeful or an accident. Right now, for once, you can tell. His knee grinds into you, makes your breath hitch, makes his grin widen, and you can tell it's on purpose.

This is where you're doing this. You're down. Literally. 

Your eyes flutter close as he keeps grinding. Zim's lips are on your cheek, your jaw. Peppered down your neck, especially careful when he meets tender skin still bandaged over. 

"That isn't happening again. On my Tallests, I swear." 

You snort. 

Zim moves down your body, soon unbuckling your pants to slip them off. They make too much noise hitting the floor. The air feels too cold. Not as cold as his hands on your skin though, feeling the curve of your stomach, the hair above your underwear. You watch mesmerized. Excited when he never seems to pay your body much notice - not as if he wouldn't! You simply love exploring his too much. 

Your hands twitch, wanting to grab your embarrassed face as your underwear goes next. Legs wanting to shut as he sits right between them. Fingers trace your inner thighs. 

"May I do as I wish?"

"Yes - Er. What… what do you wish?" 

He's grinning like a maniac. You trust him enough to smile back. You watch him shuffle back, get onto his elbows and you know what he's wanting to do. Excitement pools your gut, trying to be ready but nothing makes you prepared for his tongue licking up your groin and his lips sucking onto your clit. 

"Zim…" His gloves are soft under your hand when you find them. You try to get them around his and you only succeed when he realizes you want to hold his hand. He squeezes your fingers. Licks you again before dipping his tongue inside of you. It makes you choke. 

It feels so unnaturally long. You chalk it up to having never actually had someone eat you out before. Properly. There'd been sloppy attempts where you had to fake finishing because it was so awkward it just needed to be over with. You don't see yourself faking for Zim. Your hips arch up into his mouth. This is going to be very real.

Your eyes flutter shut at what feels like Zim's tongue curling. Flattening back out _ deep _ inside you. Which isn't possible. The sensation of it carefully pushing your cervix can _ not _be possible but you still moan from it. Loud. How full, stimulated you feel is unreal. 

At least the obvious smile on Zim's face you can be certain of. And the static already starting at your feet, crawling up your body the rougher his tongue seems to push inside, your hips pushing back. It seems to get harder with each groan of his name. 

You've never come so fast. You attempt to tell him, tugging on his hands, feeling his eyes watching you, but you just get out half a warning before the pool in your stomach comes out. Zim doesn't seem to mind, not moving from his spot until you feel breathless. His tongue slipping out is a sensation you don't think you'll forget. None of this is.

"You… didn't have to do that." 

Zim giggles, wiping his mouth off on his sleeve. "I wanted to."

"Oh." You shuffle under him. Head rests properly on your pillows. "Well… thanks." 

"You taste awful," he giggles again, reaching over your head. "I wasn't expecting you to taste _ good _ however. The makeup of human cum isn't designed to be pleasant on the mouth." You aren't quite sure how to respond to that. Besides shrinking into the pillows so he can grab whatever he's grabbing. You should probably be grateful he hated the taste but kept going -- God, his tongue was _ completely _ in you. 

Zim scoots back. "How does this work-- Oh!" The toy you'd impulse bought, forgot about, nearly cried over seeing in the mail, now being held by Zim, is fiddled with. "It goes on you, correct?" He undoes one of the buckles, already redoing it around your hip. 

"Yeah, you've got it." At the time you'd unboxed it, you were certain it was a waste. Like Zim would want to ever be on the receiving end, no matter how much you immediately wanted to have him under you when you were knuckle deep in him. Someone had to get fucked somehow and you were too giddy about it being him. 

But he's clearly into this. You're completely strapped in, amazed at how easily he figured out where everything went. Well, he is a guy who does his research. 

Your jaw clenches looking down your body at the bright pink cock jutting out of it, Zim hovering next to it, getting his leggings off. In your hands, it had looked so… average. The listing online certainly said it wasn't too big, in length or girth. You weren't wanting to hurt him after all. However, on you, compared to him… it's huge. It looks like it's going to rupture his intestines. And you don't know if he understands that.

"Don't forget to use the lube," you manage. You reach for the bottle, shoving it at him. "Don't worry about how much you use. Go… go crazy."

Zim gives a very firm nod, pushing his hoodie over his groin. Oh that's adorable. Is he shy? He seems so with how careful he opens the bottle, looks at how the lube come out onto his glove. Or… right he's nervous about an allergic reaction. You pray he won't break out. Neither of you need to have another emergency room trip because of being stupid in bed. 

He trusts the lube, going ahead and coating you in it. The cold liquid runs down your skin. You shiver. You hope it's enough. 

"It… goes inside me, right?" Zim sits on your hips, looking over his shoulder. "Right?" 

"Yeah-- but like. Slowly. Don't rush it." 

"Obviously." _ Obviously _. 

You hold your breath as he reaches back. You know when it starts to slip inside him by the flutter of his eyes. "You… You don't have to take it all yet, okay? Ease into it." If he's listening. He isn't. You know he just flattened out on your groin and he's definitely shaking. His teeth are clenched. "Zim! Jesus, I said -- are you okay?" 

He just sits there, breathing. Eyes wide and wet. He eventually nods. "It's -- it's _ inside _ me." 

"It definitely is." 

He feels his stomach. "I haven't had something inside me before." He gives a very genuine, quiet whimper. "I can feel it right against my squeedlyspooch." And before you can ask whatever the hell _ that _means, he's keeling forward, sounding like he might cry. "Fuck...fuck..." 

You panic. "Zim, I'm so sorry! We can try this some other time. I really didn't mean for your first time to be so…" Can you say big? You specifically got this strap because it wasn't too big. You just forgot how utterly tiny your boyfriend was. "I didn't mean to hurt you."

"It doesn't hurt." 

"Huh?"

Zim leans back on his hands. Pulls his hoodie so it keeps him hidden as he does. "It feels… good. Really good. So good." He cants his hips forward. Shakes. "I feel something… primal. Something I shouldn't." 

"You should feel good." You reach to rub his thighs. "I'm glad you're okay." You swallow harshly. "...Can I see?" 

Zim stares at you completely confused. 

Why does he always make you say it? "Can - Can I see where it's inside you?" 

He tugs his hoodie further down. "Are you supposed to see? Why… Why would you need to? You don't need to." He speaks fast, clearly embarrassed. 

"I don't need to. I just… want to."

"You don't want to see this." 

"I think I do." 

Zim chews on his lip. It's Zim you're with now. He isn't someone to let himself budge from a no. And you're someone he can trust would take the no. If he really doesn't want you to see, you'll live with not seeing. You just want to enjoy this however makes him comfortable. 

He seems to growl. "You were going to find out anyway." 

"Huh?" 

Zim lifts the hoodie up to his chest. It shows off the sweat dripping down his skinny teal frame, trembling just barely under your gaze. His stomach bulges just enough to tell you how deep the strap sits inside him. With how he's leaned back, the pink strap can just be seen inside him and you were right about how nice it could look against his skin. But it's not what you end up gawking at. 

Above where the strap dips into him, where his clit would be, should be, is a long curled tentacle - Can you call it a tentacle? Is that what you're looking at? An actual _ tentacle _? A dark green one that drips blue fluid and. He really did cum blue. The stains in your car wasn't some slushy you'd forgotten about.

"Oh my God?" 

That's what makes it all click. The little eccentricities that made you fall in love with Zim in the first place that now make you feel like a total moron. 

"Z-Zim. Are you. Jesus, you're an alien." 

He hisses. "Irken." 

"Irk--" You hold your face and have to laugh. "I'm so stupid."

"Don't be upset at yourself. My disguise was quite incredible." 

You're a complete moron. And then you thought someone had hurt him to make him so scared -- "Do Irkens not have sex?" 

"No." Now he chooses to be blunt and honest. "They programmed such a basic instinct out eons ago. Or I thought they did. Being around you horny, gross humans might have triggered… something." 

_ You humans. _He really is an alien. You're dating an alien.

You're fucking an alien. 

Another growl. "I'm not supposed to be…" He seems at a loss of words. It'd make two of you.

"Horny?" 

"...Yes." 

But… it's still Zim. Isn't it? Even with the world-altering realization he's not even human, that it's just humans out in this big scary universe -- You just wanted to fuck your adorable little boyfriend. You don't want to open your mind more now. You might pass out. 

"... You're old."

"Very." 

"And I was the first thing to ever make you cum?" 

He notes the smirk in your voice. "Don't get cocky, human." 

"But that's what you're here for, right?" You arch your hips up, just enough Zim gasps and holds his stomach. "Alien or human, we're still doing this."

"...You still want to do this? With me?" He gives you a confused look. "You don't want to… hurt me? Or dissect me? Or kill me?"

"Oh God, no. Zim, you're still my boyfriend." 

His face is priceless. Mouth agape, looking away, looking at you. "I… oh." 

"As long as you want to be with me, you can be a ghost for all I care." 

Zim grins. He's cupping your face, kissing your face, grunting because the sudden movement has to shift the plastic cock in him but he still kisses you. "Zim wants to be with you. You're the single greatest human I've met on this stupid planet." He's purring deep in his throat. "And I _ want _ you to breed me until I feel sick."

You can't help but giggle. The butterflies are suffocating. "I will." 

There's something new between you as Zim starts riding your hips. As he stares into your face with hazy eyes. He looks so much more relaxed, so less bothered. You feel less bothered. You were so worried about the things he didn't want to tell you, the things he kept hidden no matter how close you thought you'd gotten. Like there was a wall that would always keep you out and you had started to accept that. 

But now there's no walls. You know the both of you enjoy it better without them. 

Zim's… cock? His cock twitches against your stomach. It smeers blue over your skin as Zim bounces, groans much louder than back in the car. He sobs as you try to touch it, the tentacle wrapped tight around your fingers. 

"Is… Is this ok?" 

"Yes! Touch me -- fuck me -- anything!" His eyes shut tight as you start stroking the tentacle. It seems to be getting wetter in your palm, squeezing you harder. "Perfect… incredible…" His head hangs. You can see his tongue lolling out. He's _ really _ into this. 

"Close yet, Zim?" 

He just nods, yanking at your shirt to keep himself up. 

You smile. You want to push him but this is enough. You can't imagine how he feels right now - you can try, mind buzzing over everything still, but you're not the alien experiencing his primal urges for the first time in his life. You're just another horny human watching him fall apart as he teters closer and closer--

Zim sobs your name as he keels over your body. His hips stop riding. They just tremble like the rest of him. Even his cock that completely drenches your hand in a much thicker liquid before untangling from your fingers. 

You know for certain it's over, he's okay, when shaky arms are going under you, hugging you. You hug Zim back. Your fingers gently run through his hair. 

A low set of clicks comes from the alien on you. They gradually morph into words you understand. "Thank you." He pauses, sitting up enough to face you. "...I might love you." 

"You didn't just imprint on me did you?" you joke, brushing the hair from his wet face. You add, when he doesn't seem amused, "I love you too." 

He smiles like a complete goof and tucks into your neck. The purring is so heavenly.

"I think I did." 

"Hmm?" you hum. You hands lock on the small of his back as he adjusts, chin resting on his crossed arms. 

"I think I imprinted." 

"... Is… Is that an Irken thing?"

He shrugs. Only smiles too big. 

You stare at him. Then snort. "You better have because I have no intention of letting you go any time soon." 

He grins. "Zim is irresistible."

"Fuck yeah he is."

He laughs too quickly and you most definitely are completely in love with an alien. Dib's going to be so jealous when you tell him. 


End file.
